 (function(doc, win){
        var docEl = doc.documentElement,
            resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
            recalc = function(){
                var clientWidth = docEl.clientWidth;
                if(!clientWidth) return;
                docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';
            };
        if(!doc.addEventListener) return;
        win.addEventListener(resizeEvt, recalc, false);
        doc.addEventListener('DOMContentLoaded', recalc, false);
    })(document, window);